The teeth-chattering, bone-rattling cold is holding steady over the Bay State today thanks to wintry blasts sending wind chills even lower than Wednesday, forecasters said.

As of 8 a.m. today, all but two cities in Massachusetts had below-zero wind chills. Worcester saw the state’s most frigid wind chill of 21 degrees below zero, meteorologist Alan Dunham said. The state’s highest wind chill was one degree below zero in Chatham. There was only one place warmer, Westfield, which was balmy by comparison at 4 degrees, with winds too light for wind chill to apply.

Officials are unsure whether the cold played a role in a 5:50 a.m. brake failure on a train on the Newburyport/Rockport commuter rail line, which caused residual delays up to an hour for two following trains.

Two trains on the Haverhill line were canceled because of an equipment shortage from the trains held up on the Newburyport line, said Massachusetts Bay Commuter Rail Co. spokeswoman Rhiannon D’Angelo.

A few additional inbound commuter rail lines saw 15- to 20-minute delays, with a Framingham/Worcester Line’s slowdown due to mechanical failure just before 8 a.m. this morning, and a track problem on the Providence/Stoughton line just after 8:30 a.m., the MBTA reported.

Costas Katemis sold fruit near South station to Joe Guinta of Westwood.

Commuters riding the bus also saw delays after three buses were removed from service because of mechanical issues after 8 a.m., MBTA spokesman Joe Pesaturo said. Officials would not say if cold weather was a factor. The delays impacted Routes 7 and 47 just after 9:30 a.m.

One day after an electrical problem shut down service for three hours, the only issue on the Green Line was a disabled inbound train on the D Line at Waban Station just after 9 a.m., causing 15-minute delays, Pesaturo said.

Today will stay cold with wind chills at or below Wednesday’s with highs in the teens and winds gusting over 30 miles per hour.

This evening’s commute isn’t looking pretty, either, as winds pick up this afternoon and temperatures drop as the sun sets. Dunham recommended that those brave enough to venture outside this evening dress in layers, and wear hats and mittens.

“The mittens aren’t great for dexterity, but they keep your hands much warmer than gloves” because keeping your four fingers together helps you to retain body heat better, Dunham said.

The wind will stick around through the evening, and though Friday will be windy, highs will be in the 20s, lessening the bite of the wind chill.

This weekend will see a slight warming trend and less wicked winds. Daytime highs will increase in 5-degree increments, with Monday’s highs in the 30s.

In Boston, the Menino administration said, the Inspectional Services Department has responded to 644 calls for no heat in apartments and homes.

Under state sanitary code, temperatures in a home must be at a minimum of 68 degrees during the day and 64 degrees after 11 p.m.